Just eight days remain until the non-waiver trade deadline, which leaves teams looking to bolster their playoff hopes or pick up some prospects a little over a week to swing a deal. After our look at the market for starting pitchers, we shift our focus to the bullpen, where a number of big names, including Huston Street and Jason Grilli, have already been moved. Let's take a look at the top right- and left-handed relievers on the block, ranked by their potential impact (Note: Former Texas Rangers RHP Joakim Soria was previously listed, but he was dealt to the Detroit Tigers on Wednesday):

Right-handers

The Red Sox’ recent surge (they won eight of nine before losing to the Blue Jays on Tuesday night and falling back into last place) had them debating whether or not to sell at the deadline, but Uehara’s stock is too high and his future is likely too short for Boston to pass up an opportunity to cash in on last year’s American League Championship Series Most Valuable Player. Uehara’s ascension to closer last year and dominance in the postseason (7-for-7 in save opportunities, one run, no walks, and 16 strikeouts in 13 2/3 innings) finally made him a star in the States, and his continued excellence this season made him an All-Star, but he’s been dominating major league hitters for six years now.

For his career, Uehara's rate stats include a 2.31 ERA, 185 ERA+, 10.6 strikeouts per nine innings, 1.2 walks per nine, and an 8.89 strikeout-to-walk ratio. In the last three years, those numbers have been 1.38, 298, 11.7, 1.0, and 11.28. However, Uehara is 39 years old and a free agent at the end of the year. The Red Sox have said they want to retain Uehara as their closer in 2015, but it wouldn’t be unheard of for them to trade him then re-sign him. One thing’s for sure: His trade value will never be higher.

Benoit ascended to the closer role with the Padres in the wake of the Huston Street trade, and while he has yet to have a save opportunity in that role, he did save a game in April and notched 24 saves for the Tigers last year. One of the top set-up men in the game, Benoit has posted a 164 ERA+ and 4.12 strikeout-to-walk ratio (10.3 K/9, 2.5 BB/9) over the last five seasons, with similar numbers this year, and is signed through next season (at $8 million) with a club option for 2016 ($8 million with a $1.5 million buyout) that will vest if he finishes 55 games next year. The only real caveat there is that Benoit is 36 and will thus be 38 in that option year. The list of teams interested in Benoit adds Cleveland to the aforementioned Tigers and Pirates. Meanwhile, the Padres will be seeking a significant return not unlike their take in the Street trade.

The continued erosion of Papelbon’s velocity and strikeout rate has not impacted his effectiveness as a closer this season, as he has converted 23 of 26 save opportunities, an 88-percent success rate that’s an exact match of his career rate. He has, however, been pitching in a great deal of luck with regard to both balls in play (.229 BABIP vs. .280 career) and home runs (just two percent of his fly balls leaving the park despite a career rate of six percent and an extreme flyball rate). Add his guaranteed $13 million salary for 2015 and an option for the same salary in 2016 that would vest with 55 games finished next season (or 100 in 2014 and ’15 combined), and there are many reasons for buyers to be wary of the 33-year-old Papelbon.

Papelbon's limited no-trade clause (he can block trades to 17 teams) further complicates things, though Papelbon said early this month that he’d waive the clause to join a contender. Papelbon was shopped aggressively by the Phillies over the offseason. As one scout told me before the season, “If [the Phillies] could find a buyer, they would sell him in a heartbeat.”

Left-handers

The sixth overall pick in the 2006 draft, Miller was a bust as a major league starter, but he has grown into a dominant lefty in the Red Sox’ bullpen over the last three seasons, narrowing his pitch selection to his mid-90s fastball and wipeout slider. Thus far this season, the 29-year-old Miller has posted career-best strikeout and walk ratios (14.4 K/9 and 2.8 BB/9 for an excellent 5.08 K/BB), held lefties to a .161/.217/.232 line, and has been only marginally less successful against righty hitters. He’s flat-out dominant, and could be viable as a closer, full-inning set-up man, or matchup lefty.

As with Uehara, the Red Sox may be hesitant to part with Miller, who would like to stay in Boston, but his impending free agency means that their separation need not be permanent. Any team in baseball would be improved by adding Miller, and many have inquired about him. One team that has been named in multiple places is the Braves, whose only active lefty reliever is rookie ChasenShreve, who made his major league debut on Saturday.

Speaking of left-handed former starters who have found success in relief, the formerly erratic Perez has excelled for the Diamondbacks in the first year of a two-year contract, posting a 1.96 ERA and striking out 10.1 men per nine innings against a low-for-him 3.2 BB/9. Perez is making peanuts ($1.75 million this year, $2.5 million next), which makes him a particularly attractive option, and while he has a slight reverse split this season (LHH: .250/.308/.367; RHH: .187/.299/.280) the key piece of information there is that he, like Miller, doesn’t need to be pulled from the game when a righty steps to the plate. Expect the 32-year-old Perez to follow lefty Joe Thatcher out the door and for the Braves, again, to be among his to suitors.

The Astros could wind up getting something for nothing by trading Sipp, who they signed as a free agent in early May after he was released by the Padres. Sipp has excelled for Houston since, posting a 2.45 ERA (165 ERA+), 0.82 WHIP, and striking out 12.6 men per nine innings against 2.1 walks for a 5.86 strikeout-to-walk ratio. His splits against lefties, meanwhile, are eye-popping. In 57 plate appearances against Sipp this season, lefties have collected just five hits (three singles, a double, and a home run) and drawn five walks for a .098/.179/.176 line. There’s a ton of luck on balls in play there, as his strikeout rate is actually higher against righties, whom he has also handled effectively. But did you see where I wrote that he had allowed just five hits to lefties this season? Five hits!

The 31-year-old Sipp is making the league minimum and actually has one year of arbitration left before hitting free agency. Any team in need of a matchup lefty that doesn’t at least inquire on Sipp, who is indeed drawing significant interest, is not doing its due diligence.

The top lefty in the bullpen for the 2005 World Champion White Sox, Cotts had his career interrupted by a series of injuries, including Tommy John, a torn labrum in his right hip and ensuing infections resulting from the initial hip surgery. Since returning to the majors in 2013 after a three-year absence, he has reestablished himself as a valuable lefty, and with the Rangers' season lost and the 34-year-old Cotts due to become a free agent at the end of the year, it would be a shock to see him remain in Texas through the end of the season.

Over the last two seasons, Cotts has struck out 10.4 men per nine innings against 3.2 walks with a Fielding Independent Pitching ERA of 2.42. However, he has also exhibited a consistent reverse split, with lefties hitting .270/.343/.429 against him this season (partially the result of bad luck on balls in play). That may depress his value to teams looking for a match-up lefty, but, as with Perez, the flip side of that split is that he can hold his own against righties. Cotts may not bring much return to the Rangers, but with Texas having already dealt Jason Frasor to Kansas City earlier in the month, a trade of Cotts seems inevitable.

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